The aim of the proposed research is to explicate the development of organized event representations, and thereby, the ability to recall past events, by one- to two-year old children. This age period is particularly important because it traditionally has been thought to involve a change from purely sensorimotor to symbolic or representational functioning. Recent empirical evidence suggests, however, that children older than two years already have organized representations of events, and that children in the first year of life have the ability to recall at least isolated aspects of events. These observations place the onset of the ability to construct and maintain organized representafions of events in the one- to two-year transition period. In spite of the obvious importance of developments in memory during this time, we know little about event representation and recall by children in this age period. The results of work to date confirm that one- to two-year olds construct organized representations of events. Questions remain, however, as to whether children across this age range are able to maintain organized representations over time. The proposed research is designed to address this critical point. Three objectives are central. The first objective is to map the time course of remembering and forgetting of specific events by children in the transition from infancy to early childhood. This will establish the absolute limits on the ability of children in this age range to maintain organized representations over time. The second objective is to determine the schedule on which young children become sensitive to the factors known to influence the organization of event representations in older children and adults, namely, familiarity and the type of temporal relations inherent in the event. The third objective is to establish how the development of sensitivity to these factors influences the ability to accurately recall events that happened in the immediate as well as the remote past. Ten experiments will address these major objectives in samples of children ranging in age from 11 to 20 months. Because the children are largely pre- and early-verbal, the nonverbal technique of elicited imitation of action sequences will be used to assess recall, both immediately and following delays of up to one year. In addition, habituation/dishabituation methodology will be used to provide converging evidence as to children's sensitivity to different types of temporal relations in events. The results of these studies will not only inform theories of memory development, but by explicating the development of organized knowledge structures, general theories of cognitive development as well.